In reply to Will Monroe.

There are now so many that it's difficult to filter through them and choose. I appreciate mastodon.social as the one that Eugen, the originator, set up as I suspect it's likely to be one of the longest lived. http://indieweb.social/ has a solid IndieWeb focus and community around it. I've heard mostly good things about https://scholar.social/ from academics, though I hear that they're not fans of cross posted content from other places, including syndicating content from your website. Be sure to read the community guidelines for whichever you do join as some can be quite quirky.